1. Field of the Invention
The present invention relates to a disk cartridge in which a disk, i.e., an information recording and reproducing medium, is enclosed to prevent the disk from being contaminated.
2. Description of the Related Art
FIG. 1 is a diagram of a conventional disk cartridge. The conventional disk cartridge includes an upper case 11 and a lower case 12, which rotate about a rotational axis 14 to be opened or closed, and a disk receiving space, which is formed between the upper and lower cases 11 and 12 and receives a disk D. Accordingly, if a data recording/reproducing process needs to be performed in the disk D, the upper and lower cases 11 and 12 in which the disk D is received are coupled to each other as shown in FIG. 2 and then are loaded into a disk drive (not shown). If the disk D needs to be replaced with a new one, the upper and lower cases 11 and 12 are detached from each as shown in FIG. 1 and then the disk D is withdrawn from the upper and lower cases 11 and 12. An opening 12b is formed in the lower case 12 to allow an optical pickup (not shown) within the disk drive to access the disk D in the disk cartridge. A shutter 13 closes the opening 12b, but opens the opening 12b when the disk cartridge is mounted on the disk drive. An elastic hook portion 11a is formed on the upper case 11 and is engaged with a locking portion 12a formed on the lower case 12 when the disk cartridge is closed. If the disk cartridge is opened, the elastic hook portion 11a is elastically deformed and slightly lifted so that the elastic hook portion 11a can be disengaged from the locking portion 12a. 
The conventional disk cartridge must be opened and closed whenever the disk D is replaced. As most disk cartridges recently become thinner, it is not easy to hold the upper and lower cases 11 and 12 of the thin disk cartridge in and open the upper and lower cases. Furthermore, the elastic hook portion 11a may be deformed or damaged due to frequent opening/closing operations for disk replacement, resulting in the need for a new disk cartridge.